Air-brake for automobiles.



No. 655,654. I. L. HAMMOND.

' AIR BRAKE FOR AUTOMOBILES.

[Application filed Apr. 30, 1900.)

Pat entad Aug. 7, 1900.

(No Model.)

Wain ess es I. LHa/mmond, TnT/Entori ms NORRIS PEYERE co. m 'sroumo. WASNINGTON. u. c.

'rnrns Pn'rnr AIR=BRAKE FOR AUTOMOBILES.

SPECIFICATION forming part of Letters Patent No. 655,654, dated August7, 1900.

Serial No. 14,934. (No model.)

To all whom it may concern.-

Be it known that I, IRVING L. HAMMOND, a citizen of the United States, residing at Lewiston, in the county of Androscoggin and State of Maine, have invented a new and useful Air-Brake for Automobiles, of which the following is a specification.

This invention relates to air-brakes in genoral, and more particularly to that class especially designed for motor-carriages or automobiles; and it has specific reference to the means for automatically regulating the pressure in the storage-tank and for supplying air thereto, so that it may be maintained at the proper point.

One object of the invention is to provide a simple and efficient construction which is operatively connected with the motor-shaft and which when the pressure in the storage tank or reservoir has reached the proper point Will be automatically held from operation and will be released when the pressure drops.

Further objects and advantages of the invention will be evident from the following description.

In the drawing there is shown a side elevation of a complete mechanism embodying the present invention and illustrating the application thereof to a vehicle.

Referring now to the drawing, 5 represents the floor of an automobile, and 6 the front of p the seat-box, while 7 represents the back of the seat-box. Within the inclosure of the seat-box is disposed a motor 10, which in the present instance is shown as a fluid-pressure engine, although it will be understood that it may be an electric motor, and which motor comprises a drive-shaft or crank-shaft 11,

having a crank 12, to which is connected the pitman 13 of the engine, the crank-shaft having connection with the drive-axle 14 of the vehicle through the medium of achain 15, engaged with sprockets 16 and 17, or in any other suitable manner.

A brake-drum 18 is fixed upon the axle 14 and is encircled by a brake-band 19, one end of which is attached to a fixed support 20 upon the frame of the vehicle, while the other end is engaged with the piston-mod 21 of a brake-cylinder 22, this brake-cylinder being of ordinary construction and containing the usual piston 23, attached to the piston-rod referred to. The brake-band between the drum and its connection with the piston-rod is passed over a guide-roller 24. Thus as the piston 23 is moved in one direction the brakeband will loe drawn to exert friction against the brake-drum, and when the piston is moved in the opposite direction the band is released to release the drum and permit the drum to rotate freely.

In order to operate the piston 23 in the brake-cylinder, an air-reservoir 26 is'provided, this reservoir being connected with the brake-cylinder through the medium of a supply-pipe 27. In the pipe 27, above the brakecylinder, is located a three-way valve 28, from the casing 'of which leads a by-pass 29, communicating with the brake-cylinder, and at the opposite side of the valve-casing from the by-pass is an exhaust 80. The plug3l of this valve28 has a transverse passage 32 therethrough and is so positioned that when turned into one position its passage will communicate the supply-pipe directly with the brake-cylinder to supply pressure thereto, and when the plug is turned into its second operative position it will cut off'the supplypipe and will'communicate the by-pass 29 with the exhaust 30. A handle (shown in dotted lines) is provided for manipulating the valve-plug.

To the frame 35 of the engine is attached a supplemental frame 36 of any suitable form and comprising a base 36 and cross-pieces 37 and 38, and upon the base 36 is'mounted the pump-cylinder 40 for supplying pressure to the reservoir and which cylinder and reservoir are connected by a feed-pipe 41, including a check-valve 42, the pump-cylinder having also a valved inlet-opening 43, as shown.

A piston 44 is mounted in the pump-cylinder and has a piston-rod 46 connected therewith, this rod being extended through an opening in the cylinder-head and through an alinin g perforation in the cross-brace 37, this por tion of the rod being formed cylindrical, as shown. The outer end of rod 46 is crosssectionally rectangular, as shown at 47, and slidably engages a slot through the brace 38, and between the end of the pump-cylinder and the shoulder formed at the adjacent end of the portion 47 of the piston-rod is disposed a helical spring 48, which acts to hold the piston-rod normally projected. At the outer end of the piston-rod is pivoted a wear-block 49, which lies against an eccentric 50 upon the engine-shaft, so that as the shaft is rotated the eccentric will move the block, and therewith the piston-rod and piston, in one direction, and will then release the block to permit the helical spring to move the piston outwardly. The outward movement of the piston-rod under the influence of the spring acts to draw air into the pump-cylinder,while the inward movement thereof under the influence of the eccentric acts to compress the air in the pump and force it into the reservoir.

When the pressure in the reservoir has reached a predetermined point, it is of course desirable to cut 0E further supply of air thereto, and this is accomplished in the present instance by automatically locking the pistonrod of the pump in its retracted position, so

that the operating-eccentric may rotate freely of the wear-block. For this purpose a latch,

including a stem 53 and a head 54, has the lower end of its stem pivoted to the cross piece or brace 37 in such position that the end of the head of the latch may move into engagement with a notch 55 in the face of the portion 47 of the piston-rod when the rod is retracted, the latch being held normally and yieldably from such engagement by means of a spring 56, mounted upon the brace 37 and bearing at one end against the stem of the latch.

.A'latch-operating cylinder 57 is mounted also on the base of the supplemental frame and is connected atone end With the reser- I voir, as shown, and in this cylinder is disposed a piston 58, having a rod 59, which projects through an opening in the end of the cylinder, and between the piston and this end of the cylinder is disposed a helical spring 60, which encircles the rod and acts to hold the rod normally retracted. Under the influence of the proper pressure of air in the reservoir the piston is forced forwardly, and its rod engages the laterally-projecting head of the latch and moves the latch pivotally to press the opposite end of the latch head against the face of the outer end of the piston-rod of the pump, so that as the rod moves the latch will snap into the recess therein and will hold the rod retracted. When the pressure for the reservoir drops below that of the helical spring in the latch-operating cylinder,

the latch-operating rod is retracted to release the latch and permit its spring to move it from its engaging position. The wear-block then moves against its eccentric, and the pumping operation is repeated. Thus it will be seen that the pump will be automatically thrown into and out of operative relation to the engine-shaft and that a drop in pressure Y of rotation of the cam for operation thereby,

said rod having notches therein, a pivoted latch for engagement with the notches of the rod to hold it retracted from its operative relation to the cam, a cylinder connected with the reservoir and provided with apiston, and a rod for the piston disposed for engagement with the latch to move the latter to engage a notch of the pump-rod.

2. In an air-brake, the combination with the reservoir, of a pump connected therewith and including a piston provided with a notched rod, a rotatable cam for engagement with the rod to operate it in one direction, means for holding the rod yieldably in operative relation to the cam, a pivoted rocker having a head for engagement with the notch of the rod to hold the latter retracted, means for holding the latch normally inoperative, a cylinder communicating with the reservoir to receive pressure therefrom, a piston in said cylinder and having a rod for engagement with the latch to move it into operative position, and means for holding the said piston normally retracted.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

IRVING L. HAMMOND.

Witnesses:

W. H. NEWELL, ALICE J. BRADBURY. 

